If 40% of the portfolio is invested in the common stock, the portfolio beta is a) 1.50. b) 0.75. c) 1.00 d) 0.60. The risk free rate is 3%, the market risk premium is 9%. The Beta of General Motors (GM) stock beta is 0.80. What is the required rate of return on GM stock according to the CAPM? a) 3%. b) 9%. c) 10.2%. d) 12%